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Introduction to Ratio Tables

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Presentation on theme: "Introduction to Ratio Tables"— Presentation transcript:

1 Introduction to Ratio Tables

2 Warm Up Write the ratios as fractions in lowest terms.
OBJECTIVE: SWBAT solve ratio problems by using a ratio table. Language Objective: They will write about their understanding of ratio equivalence. Write the ratios as fractions in lowest terms. 1. The number of red bears to all gummi bears. 2. There are 4 vans and 12 cars in a parking lot. Write the ratio of cars to vans. Answer (Time on this slide – 5 min) Time passed 5 min In-Class Notes Students will need to know how to write ratios in fraction form and to always simplify. Encourage them to pay attention to the order of the ratio. Preparation Notes This should only take 3-5 minutes. It is a quick review. 3. There are 20 pens and 8 pencils in Li’s pencil box. Write the ratio of pencils to pens. Answer Answer

3 Launch Andrea and Luis are mixing red & yellow paint to make an orange color to paint their classroom door. They each think they have the perfect shade of orange. (Time on this slide – 1 min) Time passed 7 min In-Class Notes Very brief re-introduction to the on-going narrative. Students can be asked what they remember about Zack’s orange in anticipation of the next slide. Preparation Notes Abby and Zack and the orange paint will continue to be an ongoing narrative connecting these early ratio problem-solving lessons.

4 1:3, 1 to 3 or 1/3 3:5, 3/5 or 3 to 5 1:3 3:5 Launch
Andrea’s orange is made with one cup of red paint for every 3 cups of yellow paint. 1. Write that as a ratio of red to yellow in your notebook. 1:3 1:3, 1 to 3 or 1/3 Luis’s orange paint is made by mixing 3 cups of red for every 5 cups of yellow. 3:5 (Time on this slide – 3 min) Time passed 10 min In-Class Notes This Is a review of all three forms for writing a ratio. Preparation Notes It will be helpful to keep track of these ratios by maybe writing them on the board for reference later. They will be used at the end of the lesson to solve the question on the next slide. 2. Write that as a ratio of red to yellow in your notebook. 3:5, 3/5 or 3 to 5 Capo

5 Launch - Strategize “recipe” definition “batch” definition Andrea and Luis are working on a larger amounts of paint in each shade of orange. At the end of the day they found this “recipe” but they couldn’t figure out whose paint it makes. Can you? 1:3 3:5 15 cups of red paint & 25 cups of yellow paint (Time on this slide – 2 min) Time passed 12 min In-Class Notes Some students (particularly ELLs) may need “recipe” defined. If so, this would also be a good place to introduce the term “batch.” Preparation Notes It may be helpful to write these two ratios next to the children’s names so that the class can refer to them at the end of the lesson when they will solve this problem. Write down in your notes any ideas you have about how to solve this problem. Capo

6 Explore – Mini-Lesson Let’s learn about another helpful tool for ratio problems. Let’s say you love to make and eat cake. Your recipe calls for two eggs and one cup of flour for each batch. If you have 6 eggs, how much flour would you need to make the maximum amount of cake? (Time on this slide – 1 min) Time passed 13 min In-Class Notes Students may mention that you can use a tape diagram to solve this. Allow the student to demonstrate and let them know that they will also be learning a new tool today. The benefit of a ratio table over a tape diagram is that you can see many equivalent ratios at the same time. Preparation Notes Capo

7 Explore – Mini-Lesson Let’s learn about another helpful tool for ratio problems. Let’s say you love to make and eat cake. Your recipe calls for two eggs and one cup of flour for each batch. If you have 6 eggs, how much flour would you need to make the maximum amount of cake? You could draw a picture. Then you could make copies until you get to six eggs. (Time on this slide – 1 min) Time passed 14 min In-Class Notes The main idea that students should understand is that maintaining a ratio preserves the “flavor” in a recipe situation. Therefore equivalent ratios are not only equivalent because of math, but because in real life they are the same taste just more or less total quantity. Preparation Notes

8 New Tool: Ratio Table Explore – Mini-Lesson Seems like this takes a long time, don’t you think? You could record the numbers for each batch in a table. Eggs 2 4 6 Cups of flour 1 3 This table gives you the same information as the pictures. But faster! (Time on this slide – 1 min) Time passed 15 min In-Class Notes Point out how the numbers correspond to the pictures. Preparation Notes We place a high value on efficiency in mathematics. Tables are more efficient than pictures. (Later, equations will be more efficient than tables.) Stress that this is the second tool for ratio problems. There is one more, double number lines. This is a ratio table. Capo

9 New Tool: Ratio Table Explore – Mini-Lesson Question: Will 2 eggs and 1 cup of flour make a cake that tastes the same as one with 4 eggs and 2 cups of flour? Eggs 2 4 6 Cups of flour 1 3 Will this and this make cake that has the same taste? (Time on this slide – 4 min) Time passed 19 min In-Class Notes Next slide prompts a class share. Wait to click through to ask for responses. Possible answers include a realization that if you double both the eggs and the flour it will taste the same because it is double the amount of cake. Students can also realize that the ratios are equivalent when writing them as equivalent fractions. Preparation Notes We will come back to this question two more times in the lesson. The video addresses this idea. The summary question asks students to reflect on this idea in another problem. Prove your answer.

10 New Tool: Ratio Table Explore – Mini-Lesson Share Out: What do you think? Do these columns in the ratio table make the same tasting cake? Eggs 2 4 6 Cups of flour 1 3 (Time on this slide – 1 min) Time passed 20 min In-Class Notes Short share. This idea will be revisited two more times in this lesson. Hopefully students will make the connection between equivalent ratios and equivalent fractions. Try to find partners who have discovered this to share with the class. Preparation Notes

11 New Tool: Ratio Table Explore – Mini-Lesson It’s true! Each column in the table is a ratio. Each ratio is equivalent. That makes cake that tastes the same. Eggs 2 4 6 Cups of flour 1 3 How do you know the ratios are equivalent? Prove that the ratios are equivalent using cross multiplication. (Time on this slide – 2 min) Time passed 22 min In-Class Notes Hopefully students will make the connection between equivalent ratios and equivalent fractions. Try to find partners who have discovered this to share with the class. The next slide will explicitly show this connection. Preparation Notes Capo

12 New Tool: Ratio Table Explore – Mini-Lesson It’s true! Each column in the table is a ratio. Each ratio is equivalent. That makes cake that tastes the same. Eggs 2 4 6 Cups of flour 1 3 2 1 = 4 2 = 6 3 Because … (Time on this slide – 2 min) Time passed 24 min In-Class Notes Make the connection between this “fraction form” of a ratio and equivalent fractions. They obey the same rules for simplifying. Preparation Notes What is different between ratios (in fraction form) and fractions? Ratios may show a part to part relationship or a part to whole relationship while fractions show only a part to whole relationship. A fraction is a specific type of ratio. Ratios will keep the one on the bottom to show the relationship between the two quantities. A ratio shows a comparative relationship between two separate quantities. A fraction is a quotient of numbers, the quantity obtained when the numerator is divided by the denominator.

13 New Tool: Ratio Table Explore – Mini-Lesson It’s true! Each column in the table is a ratio. Each ratio is equivalent. That makes cake that tastes the same. Eggs 2 4 6 Cups of flour 1 3 A cake made with 2 eggs and 1 cup of flour will taste the same as… (Time on this slide – 1 min) Time passed 25 min In-Class Notes This shows that not only are the first two columns equivalent ratios that make the same tasting cake, but all three columns, indeed any columns you make as you extend the table, will make the cake that tastes the same. Preparation Notes

14 New Tool: Ratio Table Explore – Mini-Lesson It’s true! Each column in the table is a ratio. Each ratio is equivalent. That makes cake that tastes the same. Eggs 2 4 6 Cups of flour 1 3 A cake made with 2 eggs and 1 cup of flour will taste the same as… A cake made with 4 eggs and 2 cups of flour will taste the same as… (Time on this slide - min) Time passed 25 min In-Class Notes This shows that not only are the first two columns equivalent ratios that make the same tasting cake, but all three columns, indeed any columns you make as you extend the table, will make the cake that tastes the same. Preparation Notes Capo

15 New Tool: Ratio Table Explore – Mini-Lesson It’s true! Each column in the table is a ratio. Each ratio is equivalent. That makes cake that tastes the same. Eggs 2 4 6 Cups of flour 1 3 A cake made with 2 eggs and 1 cup of flour will taste the same as… A cake made with 4 eggs and 2 cups of flour will taste the same as… One made with 6 eggs and 3 cups of flour. (Time on this slide - min) Time passed 25 min In-Class Notes This shows that not only are the first two columns equivalent ratios that make the same tasting cake, but all three columns, indeed any columns you make as you extend the table, will make the cake that tastes the same. Preparation Notes

16 Guided Practice Try this!
New Tool: Ratio Table Guided Practice Try this! PB&J Trail Mix is made by combining 7 ounces of peanuts with 5 ounces of raisins. A ratio table has been started to show this relationship for different batches of trail mix. Peanuts (in ounces) 7 14 35 Raisins 5 15 (Time on this slide – 7 min) Time passed 34 min In-Class Notes Students may be prompted in the following way? What do you notice about the numbers in the peanuts row? Do you see a pattern? Can you continue the pattern? What pattern can you find in the raisins row? How can you figure out what is between 5 and 15? Does that help you to find the next missing numbers in the raisins row? Preparation Notes Copy and complete every box with the amounts to maintain the same flavor.

17 Guided Practice Try this!
New Tool: Ratio Table Guided Practice Try this! PB&J Trail Mix is made by combining 7 ounces of peanuts with 5 ounces of raisins. A ratio table has been started to show this relationship for different batches of trail mix. Peanuts (in ounces) 7 14 35 Raisins 5 15 21 28 10 20 25 (Time on this slide - 1 min) Time passed 35 min In-Class Notes The answers will auto-fill after initial click. Students should check their work and correct any mistakes. Preparation Notes Let’s see how you did! Here are the missing values.

18 Guided Practice Peanuts 7 14 35 Raisins 5 15 21 28 10 20 25
New Tool: Ratio Table Guided Practice What method did you and your partner use to fill in the table? What do you notice about the numbers in the peanuts row? What do you notice about the numbers in the raisins row? Peanuts (in ounces) 7 14 35 Raisins 5 15 21 28 10 20 25 (Time on this slide – 3 min) Time passed 38 min In-Class Notes Select students at random (calling sticks) to answer these questions. Students are meant to discover the pattern of “counting by” the number in the original ratio. It is best if they recognize this as multiplication but they can continue to formulate this thought throughout future practice lessons when they will use ratio tables more. Multiple methods may be highlighted. Preparation Notes Capo

19 Guided Practice For every 7 oz of peanuts you have 5 oz of raisins.
New Tool: Ratio Table Guided Practice There are mathematical statements we can say with certainty about the trail mix based on this ratio table. We can say… For every 7 oz of peanuts you have 5 oz of raisins. or for every 10 oz of peanuts you have 14 oz of raisins. Peanuts (in ounces) 7 14 35 Raisins 5 15 21 28 10 20 25 (Time on this slide – 2 min) Time passed 40 min In-Class Notes Students should focus on speaking here, not writing. Preparation Notes This connects back to earlier lessons highlighting language usage for ratio situations.

20 Independent Practice Practice using ratio tables to solve ratio word problems. (Time on this slide – 15 min) Time passed 55 min In-Class Notes Students may work independently or in pairs, if you think they need more scaffolding. Preparation Notes Answer slide follows.

21 Summary Explain, in writing, why Trail Mix with 14 ounces of peanuts and 10 ounces of raisins tastes the same as one with 7 ounces of peanuts and 5 ounces of raisins. PB&J Trail Mix Peanuts (in ounces) 7 14 21 28 35 Raisins 5 10 15 20 25 (Time on this slide – 5 min) Time passed 65 min In-Class Notes Remind students to think about the cake example in the mini-lesson and the Skittles example in the video. They can refer to their notes. Similar responses would be anticipated. Preparation Notes Push students to write a response and to read their writing rather than to just think about the question. Many students like to skim over the requirement to write at the end of a lesson. Explain why this and this will have the same taste.

22 Exit Ticket Use the ratio table tool to figure out whose orange paint, Andrea’s or Luis’s, is made with this “recipe.” There is space on your worksheet. 1:3 15 cups of red & 25 cups of yellow paint 3:5 (Time on this slide – 5 min) Time passed 73 min In-Class Notes Encourage students to independently Preparation Notes

23 Assessment – Write your answers in your notes.
1) Which ratio table can be used to solve the problem below? Jenny discovers that she has 8 shirts for every 5 pants. If she has 40 shirts, how many pants does she have? shirts 5 10 15 20 25 pants 8 16 24 32 40 A. shirts 8 16 24 32 40 pants 5 10 15 20 25 B. (Time on this slide – 2 min) Time passed 75 min In-Class Notes This slide can be used as an optional assessment if the exit ticket does not sufficiently cover this purpose. Preparation Notes shirts 5 10 15 20 25 30 35 40 pants 8 16 24 32 48 56 64 C. 2) What is the correct answer to the problem?


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